1. Field of the Invention
The present invention relates to an integrated circuit device and a testing method thereof. Specifically, the invention relates to an integrated circuit device having a digital and/or analog circuit parts and a testing circuit for executing the testing of the digital circuit part and the analog circuit part, and relates to the testing method thereof.
2. Description of the Prior Art
As integrated circuits become more dense and complex, it has become increasingly important to test circuits after they have been manufactured to guarantee quality and correctness. The increase in density and complexity has also made the physical availability of pins on a microchip a problem, and it has become important to design circuits which have the reduced number of external pins used.
Although various circuit specific methods have been developed for testing digital circuits of integrated circuit devices, most modern designs employ the scan testing method. This method usually employs four or more external testing pins including a pin to select the mode of scan flip-flop circuits in the digital circuit parts to be tested in a scanning mode or a normal operation mode, an input pin for inputting control data, an output pin for outputting observation data, and a clock pin for inputting a clock signal. In addition, this scan testing method is not suited to test circuits with analog control or observation nodes.
Since the conventional integrated circuit device and its testing method are constructed as above, plural external testing pins may be required for the integrated circuit device, whereby there are problems in which the size of the integrated circuit device cannot be minimized as well as the analog circuit parts cannot be tested suitably.